Large earth screen shunt vector quantity measurement method based on wireless transmission

Abstract

The invention discloses a large earth screen shunt vector quantity measurement method based on wireless transmission, and relates to the technical field of grounding character measurement of large grounding grid of substations, electric power plants, and the like. When grounding impedance measurement of running power station and substation grounding grids is carried out, the wireless transmission technique is adopted, wireless transmission phase information is tested between current injection points and outgoing line frameworks and between the current injection points and outgoing line cable shunt measuring points, a phase between each shunt vector quantity and each test current vector quantity is obtained in real time, a pilot frequency shunted vector quantity flowing through metal frameworks and outgoing line cable outer sheaths is obtained through mathematical treatment, the metal frameworks and the outgoing line cable outer sheaths are connected with outgoing line overhead ground wires, and the pilot frequency shunted vector quantity comprises the size of a module value and a phase difference. The measurement method solves the problem that a shunt vector quantity cannot be measured on site in the past, and provides technical support for refined calculation of shunt coefficients of the running substation overhead ground wires and the cable outer sheaths.

Description

technical field [0001] The invention relates to a method for measuring grounding grids in the electric power industry, in particular to a method for measuring diversion vectors of large-scale grounding grids based on wireless transmission. Background technique [0002] In addition to providing a common reference ground for various electrical equipment, the grounding grid of power plants and substations, more importantly, can quickly and effectively discharge the fault current when the system has a ground fault or is struck by lightning, improving the ground potential distribution of the grounding grid and the site , The role of ensuring the safety of primary and secondary equipment and personnel is an important measure to maintain the safe and reliable operation of the power system and ensure the safety of personnel and equipment. [0003] Grounding impedance is an important parameter to characterize the performance of the ground grid. The definition of grounding impedance ...

AI Technical Summary

Problems solved by technology

In the past, due to the limitation of technical level and testing equipment, in many cases, when measuring the ground network of substations, either the ground wire shunt was not measured at all, or only the modulus of the metal frame shunt was measured, and its phase was not measured.

If the shunt is not measured, the impact of the overhead ground wire dispersion is not considered, and the calculated value of the final test current is too large; if the shunt size (modulus) is measured but the phase difference is not measured, all the shunts can only be regarded as scattered flow outside the ground network , and its direction is completely opposite to the test current injected into the ground grid, the calculated value of the final test current is too small; sometimes the sum of the shunt modulus values ​​measured by each metal structure has even exceeded the injected test current, which cannot Get logical test results

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